Thread cutting die and holding clip therefor



Feb. 21, 1933. Q Q, E, KOEHLER ET AL 1,898,132

THREAD CUTTING DIE AND HOLDING CLIP THEREFOR Filed July 10, 1931 J6 5flmn mp4;

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VM *M Patented Feb. 21, 1933 UNITED STATES PATENT, OFFICE OSCAR E.KOEHLER AND WILLIAM B. DU MONT, OF GREENFIELD, MASSACHUSETTS,

ASSIGNORS TO GREEN'FIELD TAP & DIE- OOZIPORATION, OF GREENFIELD, MASSA-CHUSETTS, A CORPORATION OF MASSACHUSETTS THREAD CUTTING DIE AND HOLDING-CLIP THEREFOR Application filed July 10,

This invention relates to thread cutting dies and holders andparticularly to such devices in which a set of two separate die blocksis used for cutting each difierent size 5 or number of thread.

It is customary to furnish these die blocks in sets comprising severaldifferent pairs with a single die holder, so that the different pairs ofblocks may be selectively inserted in the holder for cutting aconsiderable range of thread sizes. 7

The object of our inventionis to provide improved means for holding eachpair of die blocks in assembled relation, whether in use or in storage.I

More specifically, we provide an improved sheet metal clip in which apair of die blocks may be assembled and yieldingly secured but fromwhich the blocks may be easily removed'when desired.

Preferred forms of our invention are shown in-the drawing, in which Fig.1 is a plan view of a die holder provided with our improvements;

Fig. 2 is a sectional side elevation, taken along the line 22 in'Fig. 1;

Fig. 3 is a plan view of a blank from which our improved clip is formed;

Fig. 4 is a side elevation of the clip after the blank is bent tofinished form;

Fig. 5 is an end elevation of the clip, looking in the direction of thearrow 5 in Fig.4;

Fig. 6 is a plan view of a slightly modified form of clip;

Fig. 7 is an end view of the clamping member, looking in the directionof the arrow 7 in Fig.2; 7 i

Fig. 8 is an end view of one of the die blocks;

Fig. 9 is a. plan view of a blank used in forming a clip of a furthermodified con-- struction; I

Fig. 10 is a detail sectional view, taken along the line 1010 in Fig. 9,and

Fig. 11 is a side elevation of the clip formed from the blank shown in'Fig. 9.

Referring to the drawing, we have shown a die holder or collet 10adapted to be secured in a suitable handle or chuck. This die holder 10is provided with a rectangular 1931. Serial No. 549,941.

opening 11 having outwardly converging side walls adapted to be engagedby the beveled sides 12 of a pair of die blocks 13.

The die blocks are inserted in the holder 10 from the back side and aresecured therein by a clamping member 15, threaded'into a circular recess16 in the back of the holder. The clamping member 15 also preferablyacts as a guide for the stock to be threaded, and is provided withspaced guiding portions 17, separated by openings 18 through which chipsmay escape; Preferably, a separate guiding member 15 is provided foreach diameter of stock to be threaded.

Adjusting screws 20 in the holder 10 engage the outer end faces of thedie blocks 12 and are used to adjust the die blocks inward to correctposition to cut a thread of a desired diameter. Each die block isprovided with shallow grooves 22 (Fig. 8) in its upper and lower faces,extending longitudinally and for a purpose to be described. 2

Our improved holding clip C may be formed from a rectangular blank ofthin and preferably resilient sheet metal 30, as indicated in Fig. 3.This blank is then provided with cut out portions 31 and-32 and withlongitudinally extending displaced portions or ridges 33. After theblank is thus formed, it is bent to the open rectangular outline shownin Fig. 4:, with the openings 32 extending across the ends of the clipand with the ridges 33 directed inwardly or towards each other. 7

When a pair of die blocks 13 is assembled in a holding clip G, theridges '33 are seated blocks and clip witho'ut disturbing the adjustmentof the screws 20.

Our improved holding clip may be easily and economically manufacturedand requires no change in the construction of the usual die blocks,except the provision of the grooves 22, which are easily formed andwhich do not in any substantial way weaken the construction of the dieblocks.

The use of our improved holding clip not only retains the two die blocksof a pair in assembled relation so that they will not be mismated butalso holds the die blocks in such relative position that the cuttingteeth are not readily injured. 7

The assembled dies may also be more easily and quickly inserted in acollet orholder. While shown in connection with a removable collet, theinvention is equally adapted for use in a construction in which thecollet or holder forms an integral part of the die stock.

In Fig. 6 we have shown a slightly modified construction in which themiddle portion of the blank is outwardly enlarged or displaced to form awider opening 35. This form may be used with die blocks for cuttingthreads of larger relative diameter.

In Figs. 9, 10 and 11 we have shown a further form of our inventionWhich avoids the necessity of grooving the'die blocks. A blank fromwhich this form of our invention may be constructed is shown in Fig. 9and comprises a piece of thin resilient sheet metal rovided with anenlarged center opening 40 in the bottom thereof, with rectangularopenings 41 in the end portions thereof, with slight projections 42 inthe extreme ends ofthe blank, and with outwardly inclined flanges 43rojecting upwardly from the opposite ends of the bottom portion M of theblank.

After being thus formed, the blank is bent to the open rectangularconstruction shown in Fig. 11 and is adapted to engage and detachablysecure the die blocks in assembled relation as in the previo'usconstructions.

The flanges 43 project upwardly a suiiicient distance to engage thelower edges of the beveled side portions of the die blocks and tothereby prevent lateral displacement thereof. The slight projections 42are on the inside of the clip when the latter is bent to final positionand project slightly into the clearance openings of the die/blocks, thusyieldingly preventing the die blocks from sliding toward each other inthe clip.

Otherwise the clip is substantially similar to the forms previouslydescribed and possesses the same advantages, together with theadditional advantage that this clip may be used with the regularcommercial die blocks and without any change or addition thereto.

Having thus described our invention and the advantages thereof, we donot wish to be limited to the details herein disclosed, otherwise thanas set forth in the claims, but what we claim is 1. A screw threadingdevice comprising a die holder, a pair of separable die blocks mountedto slide in said holder, and an additional die-holding clip in whichsaid die blocks may be detachably assembled before insertion in said dieholder, said clip being formed of thin sheet metal and having portionsengaging the tops, bottoms and outer ends of said die block, said clipalso having provision for preventing lateral displacement of said blockstherefrom.

2; A screw threading die and holding clip therefor, comprising a pair ofdie blocks and aclip formed of thin sheet metal and having portionsengaging the tops, bottoms and outer ends of said die blocks, said dieblocks each having longitudinal depressions in their top and bottomsurfaces and said clip having inwardly displaced portions seated in saidlongitudinal depressions and preventing lateral displacement of said dieblocks relative to said holding clip.

3. A screw threading die and holding clip therefor, comprising a pair ofdie blocks and a clip formed of thin sheet metal and having portionsengaging the tops, bottoms and outer ends of said die blocks, said clipalso having provision for preventing lateral displacement of said blockstherefrom and having slots extending across the end portions to provideclearance for the block-engaging ends of adjusting screws.

Al. A screw-threading device comprising a die holder, a pair ofseparable die blocks mounted to slide in said holder, and an additionaldie-holding clip in which said die blocks may be detachably assembledbefore insertion in said die holder, said clip being formed of thinsheet metal and having portions engaging the tops, bottoms and outerends of said die block, said blocks and clip havingengaging portionseffective to prevent accidental lateral displacement of said blocks.

5. A screw-threading device comprising a die holder, a pair of separabledie blocks mounted to slide in said holder, and an additionaldie-holding clip in which said die blocksmay be detachably assembledbefore insertion in said die holder, said clip being formed of thinsheet metal and having portions engaging the tops, bottoms and outerends of said die block, said holding clip being open at the sides andleaving the sides of the die blocks free and unobstructed.

6. A holding clip for die blocks comprising a substantially rectangularframe of light resilient metal, said frame being open at the sides andhaving openings through the bottom and both ends and the top portiondiscontinuous and partially open, the bottom and top portions of saidclip having inwardly depressed longitudinal ridges formed there- 7. Ascrew-threading device comprising a die holder, a pair of separable dieblocks mounted to slide in said holder, and an additional die-holdingclip in which said die blocks may be detachably assembled beforeinsertion in said die holder, said clip being formed of thin sheet metaland having portions engaging the tops, bottoms and outer ends of saiddie block, said holding clip also having inwardly projecting flangesalong the opposite side edges of the bottom effective to prevent lateraldisplacement of the die blocks therefrom.

8. A screw threading die and holding clip therefor, comprising a pair ofdie blocks and a clip formed of thin sheet metal and having portionsengaging the tops, bottoms and outer ends of said die blocks, said cliphaving its bottom portion outwardly enlarged and recessed at its middlepart and having inwardly projecting flanges at each end of said enlargedportion for preventing lateral dis-7 placement of the dieblockstherefrom.

9. A screw-threading device comprising a die holder, a pair of separabledie blocks mounted to slide in said holder, and an additionaldie-holding clip in which said die blocks may be detachably assembledbefore insertion in said die holder, said clip being formed of thinsheet metal and having portions engaging the tops, bottoms and outerends of said die block, said holding clip also having provision forpreventing lateral displacement of said die blocks therefrom and havingadditional means to prevent displacement of said die blocks by slidingmovement toward each other.

10. A. screw threading die and holding clip therefor, comprising a pairof die blocks and a clip formed of thin sheet metal and having portionsengaging the tops, bottoms and outer ends of said die blocks, said clipalso having provision for preventing lateral displacement of said blockstherefrom, and having slight inwardly projecting portions at the innerends of the top members, which yieldingly prevent inward slidingmovement of said die blocks.

In testimony whereof we have hereunto aflixed our signatures.

OSCAR E. KOEHLER. WILLIAM B. DU MONT.

